Weakness, lethargy, cold intolerance, paleness, dry skin, coarse hair, and constipation can occur with hypothyroidism (see Table 1). Other symptoms may include delayed reflexes (such as the knee jerk when the knee is hit with a reflex hammer), brittle nails, increased blood pressure, and a slow heart rate.

'Some patients will feel relatively well except for tiredness. Some patients will feel extremely fatigued. Older patients have greater hypothyroid manifestations, and some patients will have a difficult time performing daily tasks. Thus, as a precaution, all patients who are hypothyroid should avoid making important decisions and driving or operating heavy machinery for one to two weeks before and after the scan or treatment

in many patients few symptoms occur in the time required to prepare for a radioactive scan or treatment or during the weeks after restarting thyroid hormone.

Patients experience a wide spectrum of symptoms during their period of temporary hypothyroidism. A few patients feel the same as before. While a few patients feel the same as before, the great majority feel considerably slowed down, Some describe it as feeling mildly sedated. They can converse and do household chores, but their reaction times are slower. They are also more prone to errors when doing tasks involving attention to details. A few patients feel more severe symptoms from among those described above.

The time of recovery from the symptoms of hypothyroidism also varies from weeks to months, and this at least in part depends on how long it takes to adjust the dose of thyroid hormone to the appropriate dose.